Jonathan Davidov and Zvi Eiskiovits at the Centre for the Study of Society in Israel conducted in-depth interviews with 20 survivors of Nazi death camps – institutions designed to destroy free will. The researchers' striking interpretation of the testimonies is that without free choice there is quite simply no existence.

The interviewees, 7 men and 13 women, now aged between 80 and 90, were questioned in their own homes about their experiences at the Auschwitz network of concentration camps. After the researchers transcribed and reflected on the accounts they found three recurring themes.

Despite living in a death camp where all freedom and individuality was removed, the interviewees experienced acute moments of choice and will when it came to the experience of "selection" – this was a ghastly recurring process whereby the Nazi captors lined up the prisoners to decide who would be kept alive for manual labour and who would be sent to execution in a gas chamber. "Despite the extreme conditions," the researchers said, "some people found a measure of situational freedom through which they could attempt to direct their lives."

Consider the experience of Israel, aged 15 at the time he was transported to Auschwitz. Taken to a selection after 48 hours without food or drink, standing half naked in the snow, he was asked by his captor to state his age:

"So I answered 'I'm a welder'. And I got this sarcastic face stuck in my mind to this very day, his smile, because he understood exactly what I was doing."

The researchers said: "A huge amount of information is telescoped into this split second. Israel contemplates his journey to the camp, thinks about his situation, and realises this is the time when he must make his final stand or die." The researchers believe that some prisoners, like Israel, made active choices to influence their destiny – exhibiting and experiencing free will – even in the grim context of a death camp. In this case, Israel ignored his captor's question and instead communicated how he could be useful, likely saving his own life in the process.

Such moments of "choice" were followed by long periods of waiting until the next selection, which brings us to the researchers' second theme. The interviewees described this time as like a frozen present. As Ora, aged 15 at the time she was a prisoner, put it:

"As there was no clock and no day or night, we couldn't tell the time. We used to sit, or stand, or wait. Wait, wait, and wait."

The only action available through these empty "borrowed times" was to wait until the next selection. Without any freedom, the interviewees described experiencing nothingness. And here is the final theme – the way the prisoners described their own and other people's response to this non-existence. Some said they managed to cope through a dulling of their emotions. "My heart became as hard as rock," said Israel. But for others the nothingness proved deadly. "Muselmann" is the German term used to describe prisoners for whom the emotional nothingness had become overpowering. As Esther explained:

"Someone who became nothing, was named a Muselmann. He was exhausted with hunger, weakness, and despair. When there is no despair, you eat something, even grass. But when there is no one to live for, what to live for, no one to support you and no one that you need to support yourself, you don’t have anything to live for. When there is no one to look after, there is no answer to the questions: 'What is it all about? Who am I and what am I? To whom do I matter?"

Taken together, Davidov and Eiskiovits said their interviews show that from a phenomenological perspective, "free will and existence represent the same concept: I choose – therefore I am. When free will is denied there is emptiness and nothingness ...".